Poor voice quality on phones 9XXX, 8XXX series

[Ruslan Kravets]

Hello!

We use CUCM 7.0 and several phones 9971, 8961 models. Some users complain of having poor sounding on their phones. It seems like cutting of upper frequencies in the handset and at the result users hear a hollow, splay sound. Does anybody know what may be a cause of this problem? Is there any abilities to tune electric parametrs of the phones handsets?

Thanks,

Ruslan

[clileikis]

Do you have any 79XX phones in your environment, if so are they experiencing the same behavior or is it just the 89XX and 99XX phones?

[Ruslan Kravets]

Yes, we have also 79XX, 6XXX phones in the same LAN but nothing issues with them. Only 9971 and 8961 have a such behavior.

[clileikis]

Hi Ruslan,

If there's no latency or jitter during the call (hit the ? mark twice on the phone during an active call with call quality issues and check the call statistics) you may want to get a TAC case opened.  We had the same issue and there were some known issues with the firmware.

[matthewtravers]

We've deployed a few 99XX's as replacements for 79XX's.  From personal experience I find the voice quality of the 99XX handsets to be no where near as good as the 79XX.